Computer-assisted weapons, such as those used for assisting in targeting a weapon, are well known. In one such system, described in published U.S. patent application number US2006/0121993, entitled “System and Method for Video Image Registration in a Heads Up Display,” hereby incorporated by reference, a video camera is coupled via a computer to a heads-up display. A computer positions images from the video camera on the heads-up display based on the relative orientations of the video camera and the display. As the video camera moves with respect to the display, the images are repositioned within the heads-up display. The video image may come from a weapon sight aligned with the heads-up display so that the user can easily view the camera image without having to shift focus from the larger scene.
FIG. 1 (taken from the aforementioned published patent application) shows a system wherein a soldier 500 is fitted with goggles 505, a rifle 502 with video gun sight 503, and field computer 501. The goggles 505 may produce a visual field for the user to see in front of him. The video gun sight 503 produces a video feed, including cross hairs, depicting the line of sight of the rifle 502. The video weapon sight 503 may produce a magnified view, a thermal view, a night vision view, an image intensifier view, or some combination thereof.
Computer 501 receives a video feed from video weapon sight 503 via cable 512. The field computer 501 receives sensor data from orientation sensors 504 and 506, via cables 510 and 511. Once the video feed is processed, field computer 501 delivers video for the heads up display within the goggles 505 via cable 513.
The sensor 504 affixed to rifle 502 sends data relaying the orientation of the weapon and attached video gun sight 503. This data may include angular pitch, yaw, and roll information, sent in frequent intervals. The sensor 506 affixed to goggles 505 relays similar orientation data, except that it reports on the line of sight of the goggles instead of the rifle 502. Sensor 504 need not be directly affixed to the rifle 502, so long as it moves with the rifle. For example, it could be attached to the gun sight 503. Likewise, sensor 506 need not be directly affixed to the goggles 505. The sensor 506 could also be attached to the helmet of the soldier 500. Instead of cables, wireless communication may be used between any or all of the various components.
FIG. 2 (taken from the aforementioned published patent application) is a block diagram which depicts functional components of a system of the type shown in FIG. 1. Computer 601 receives sensor data and a video feed from video assembly 604, along with sensor data from heads up display assembly 607. Video assembly 604 is composed of video source 602 and sensor 603 affixed to detect the orientation of the video source. Video source 602 has a visual field 611 from which it receives light and converts it to the video signal delivered to computer 601. Heads up display assembly 607 is composed of beam combiner 605 and sensor 606 affixed to detect the orientation of the beam combiner.
Beam combiner 605 has a visual field 610, whose image is combined with the processed video signal delivered from computer 601. This combination of video signal with visual field may be created through the use of a transparent display, such as a piece of glass set at an angle. The glass may pass light from the visual field 610 to the observer while simultaneously reflecting light from a video display strategically placed based on the angle of the glass. The transparent display need not be perfectly transparent, but also might be translucent allowing only some light to pass through. The video output of computer 601 is placed in front of the visual field 610, creating what is sometimes referred to as a heads up display or HUD. Such displays allow an observer to receive information or images while simultaneously viewing a visual field, preventing the observer from having to look away.
FIG. 3 (also taken from the aforementioned published patent application) shows how the field of view through the goggles can be combined with a visual feed from a video camera aligned with the weapon sight. Image 200 represents the visual field through a normal set of goggles without any enhancement. Image 300 represents the visual field (including a target crosshair 301) from the video camera capturing the same scene (or a portion of the same scene) as visual field 200. Visual field 400, here the view through a soldier's night vision goggles or other (clear) goggles, is enhanced with the addition of a portion of the weapon sight video feed 401 through the use of a heads up display (HUD) projected to one eye of the wearer. Video feed 401 may be modified so as to discard unneeded visual information, cropping the image to perhaps one quarter of its original size. In addition, the video feed 401 has been positioned over the portion of the visual field 400 based on the direction the video source is pointed. As the weapon moves, the video feed 401 is dynamically positioned within the visual field 400. Ultimately, by superimposing the two images, a soldier with a heads up display and a weapon mounted video camera is able to simultaneously survey a setting, acquire a target, and point his weapon at the target without taking time to shift from goggles to weapon sight.
Although not shown in FIG. 1, the known system of FIG. 1 also includes a switch plate comprising a plurality of buttons affixed to weapon 502, allowing the soldier to perform certain limited functions. The known assigned button functions include: (1) power on/off, (2) a video source select, permitting the soldier to select daylight video or thermal weapon sight; (3) a heads-up display brightness control, allowing the soldier to toggle brightness through various levels; (4) a calibration switch permitting calibration of the inertial measurement units; (5) a mode switch that toggles between modes including a power-up mode, a full-screen mode, a calibration mode, and a standby mode; and (6) a spare (unused) function.
It would be desirable to permit a soldier to perform more sophisticated control functions related to computer manipulation, such as for controlling a cursor on a computer screen, while allowing the soldier to maintain control of the weapon or other manipulable object.